Culture of Roundtail Chub, Gila robusta robusta (Cyprinidae), through the Larval Period

1985 ◽  
Vol 30 (1) ◽  
pp. 152 ◽  
Author(s):  
Robert T. Muth ◽  
Charles M. Haynes ◽  
Clarence A. Carlson
Keyword(s):  
Larval Period ◽  
Roundtail Chub

Cell lineage of homeotic mutants of Drosophila

1985 ◽  
Vol 312 (1153) ◽  
pp. 139-144 ◽  
Keyword(s):  
Mode Of Action ◽  
Cell Lineage ◽  
Precursor Cells ◽  
Larval Period ◽  
Homeotic Genes ◽  
Lineage Analysis

The homeotic genes specify the development of specific groups of precursor cells. They establish the correct state of determination of the different primordia. Cell lineage analysis has been particularly useful in studying the mode of action of homeotic genes. The main findings are: (i) most, perhaps all, the homeotic genes are required by every cell of the corresponding primordium (that is, they are cell autonomous); (ii) they act on anatomical units defined by compartment boundaries and including one or more compartments, (iii) most, but not all, homeotic genes are required until the end of the larval period; (iv) the homeotic genes act in combination so that the appropriate development of a given primordium may be established by the contribution of several homeotic genes.

The Utilisation of metabolic Water in Insects

1944 ◽  
Vol 35 (2) ◽  
pp. 127-139 ◽  
Author(s):  
G. Fraenkel ◽  
M. Blewett
Keyword(s):  
Body Weight ◽  
Water Content ◽  
Larval Development ◽  
Dry Weight ◽  
Larval Period ◽  
Tribolium Confusum ◽  
Ephestia Kuehniella ◽  
Final Size ◽  
Metabolic Water ◽  
Food Consumed

(1) Three insects,Tribolium confusum, Ephestia kuehniellaandDermestes vulpinus, have been grown at several humidities and the following factors have been determined: length of larval period; water content of food and of the freshly formed pupae; wet and dry weight of pupae and wet and dry weight of food consumed during larval development. The “net utilisation” of the food has been calculated as the ratio of dry weight of food eaten per larva to dry weight of pupa.(2) At lower humidities more food is eaten to produce a given unit of body weight. The length of the larval period increases and the weight of the pupae decreases.(3) More food is eaten at low humidities, because part of the food is utilised as water. As a consequence of this, the larva grows more slowly and its final size is smaller. It is shown forDermestesat 30 per cent. andEphestiaat 1 per cent. R.H. that less than 32·9 and 7·6 per cent. of the water in the pupae can be derived from water ingested with the food.

IN VIVO SYNTHESIS AND BREAKDOWN OF DEOXYRIBONUCLEIC ACID IN TRIBOLIUM CONFUSUM DUVAL

1966 ◽  
Vol 44 (12) ◽  
pp. 1571-1575 ◽  
Author(s):  
K. D. Chaudhary ◽  
A. Lemonde
Keyword(s):  
Dna Synthesis ◽  
Growth Phase ◽  
Deoxyribonucleic Acid ◽  
Total Concentration ◽  
Larval Growth ◽  
Pupal Stage ◽  
Larval Period ◽  
Tribolium Confusum ◽  
In Vivo Synthesis

The in vivo synthesis of deoxyribonucleic acid (DNA), as shown by the rate of incorporation of14C-thymidine, has been investigated at different stages in the life cycle of Tribolium confusum. During the larval period, a close similarity is observed between the rate of DNA synthesis and the pattern of growth. The pupal stage, which is a non-growth phase, is characterized by a cessation of DNA synthesis. During the larval growth phase, although the 3-day-old larvae have the lowest and the 13-day-old have the highest rate of DNA synthesis, the rate of DNA degradation in the older larvae is almost twice as great as that of the younger larvae. These findings are consistent with the observed total concentration of DNA of the insect at these stages.

NEW DESCRIPTIONS OF LARVAE OF FOREST INSECTS: SEMIOTHISA, DYSMIGIA (LEPIDOPTERA, GEOMETRIDAE)

1947 ◽  
Vol 79 (6) ◽  
pp. 113-116 ◽  
Author(s):  
W. C. McGuffin
Keyword(s):  
Transition Period ◽  
Larval Instar ◽  
Larval Period ◽  
The Other ◽  
Forest Insects ◽  
Other Hand ◽  
Larval Moult

Some geometrid larvae exhibit dimorphism in colour. Several interesting observations of this phenomenon were made during the study of larvae of the species, Semiothisa sexmaculata Pack., Dysmigia loricaria Evers., and Nepytia canosaria Wlk.In these observations, certain points stand out. Although larvae of S. sexmaculata are always green until they reach the last instar, both brown and green phases occur in that stage. After the last larval moult, a transition period of approximately two days is required for larvae to acquire the colouring of the brown phase. On the other hand, specimens of D. loricaria may pass their entire larval period in either a brown or a green phase (as do the larvae of N. canosaria, descriptions of which may be found in Can. Ent. 75: 186-189) or they may change (as do some larvae of S. sexmaculata) from the green phase to the brown phase in the last larval instar. For Dysmigia larvae to undergo this transformation, approximately three days are required.

scholarly journals Study of Morphometric Aspects of Eri Silkworm (Samia ricini D.) reared on the host plant

2020 ◽  
pp. 192-196
Keyword(s):  
Host Plant ◽  
Significant Role ◽  
Environmental Conditions ◽  
Ricinus Communis ◽  
Larval Period ◽  
Larval Duration ◽  
Larval Weight ◽  
Larval Length ◽  
Qualitative Characters

The environmental conditions play a significant role and influence the quantitative and qualitative characters of silkworm such as larval length, larval breadth, larval weight and larval duration. Larvae of Eri silkworm (Samia ricini D.) were reared on Castor leaves (Ricinus communis). The data that were recorded for larval length (cm) from first to fifth instar are 0.76 ± 0.003; 1.49 ± 0.023; 3.09 ± 0.020; 4.39 ± 0.04 and 6.57 ± 0.04 respectively, for larval breadth (cm) are 0.122 ± 0.007; 0.24 ± 0.0; 0.46 ± 0.0; 0.74 ± 0.0 and 1.14 ± 0.0 respectively and for larval weight (g) are 0.007 ± 0.01; 0.033 ± 0.02; 0.37 ± 0.01; 1.07 ± 0.02 and 3.74 ± 0.03 respectively and the larval period of the reared larvae lasted for about 20 days.

scholarly journals Interspecific Variations in Duration of Tail Regression in Two Tropical Anurans

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Cuckoo Mahapatra ◽  
Pravati Kumari Mahapatra
Keyword(s):  
Environmental Conditions ◽  
Rainy Season ◽  
Larval Period ◽  
Evolutionary Strategies ◽  
Interspecific Difference ◽  
Extreme Temperatures ◽  
Larval Phase ◽  
Morphological Variations ◽  
Interspecific Variations ◽  
Tadpole Tail

Anurans breed in an array of habitats and hence employ a variety of evolutionary strategies to adapt to the variable conditions. Particularly, since they undergo a larval phase they develop mechanisms to overcome unfavourable conditions like desiccation, extreme temperatures, and so forth. The anurans, Polypedates maculatus and Duttaphrynus melanostictus, show noticeable variation in the duration of larval period and tadpole tail regression. D. melanostictus breeds throughout the year and hence is subjected to different environmental conditions as compared to P. maculatus which breeds only during the rainy season. Thus, the tadpoles of D. melanostictus have selected to undergo a shorter larval period and duration of tail regression to suit their breeding habits. The present study correlates the interspecific difference in the duration of tail regression with the morphological variations in the tails of the two species. D. melanostictus shortens the duration of larval tail regression by having comparatively larger and more number of melanocytes and a thinner notochord than P. maculatus.

Functions of the Lymph Gland Cells during the Larval Period in Drosophila

Development ◽  
1957 ◽  
Vol 5 (2) ◽  
pp. 122-133
Author(s):  
H. H. El Shatoury ◽  
C. H. Waddington
Keyword(s):  
Adult Stage ◽  
Larval Period ◽  
Careful Study ◽  
Developmental Effects ◽  
The Individual ◽  
Recent Monograph ◽  
Mutant Genes ◽  
Considerable Body ◽  
Lethal Genes ◽  
Epigenetic Processes

A Considerable body of information has already been accumulated in which a careful study of the morphological effects of a gene in Drosophila has been used to throw light on the epigenetic processes which bring about development. Much of the earlier work of this kind (e.g. Goldschmidt, Waddington) has dealt with mutant genes which produced abnormal adults. More recently a great deal of attention has been paid to the developmental effects of lethal genes which cause the death of the individual before the adult stage is reached. In a recent monograph on this category of genes, Hadorn (1951), who has been one of the most active workers in this field, lays considerable stress on what he calls the phase specificity of the lethals, that is, on the fact that individuals homozygous for a particular lethal usually die at some rather definitely defined stage of their life history.

Development of the Intestinal Tract during the Larval Period of Drosophila

Development ◽  
1957 ◽  
Vol 5 (2) ◽  
pp. 134-142
Author(s):  
H. H. El Shatoury ◽  
C. H. Waddington
Keyword(s):  
Salivary Glands ◽  
Intestinal Tract ◽  
Larval Period ◽  
Lethal Mutant ◽  
Lymph Glands ◽  
Periodic Processes ◽  
Drosophila Larvae ◽  
Hind Gut

This paper is concerned with certain aspects of the development of the mid-gut (stomach), hind-gut, and salivary glands of Drosophila larvae. Attention will be particularly concentrated on two types of phenomenon, firstly, on periodic processes of hypertrophy and regression which affect certain of the larval tissues comprising these organs, and, secondly, on the development of groups of imaginal cells which, at metamorphosis, produce the tissues from which the adult organs are built up. There is evidence that in the control of both these processes an important part is played by the lymph glands. This evidence is derived primarily from the study of certain lethal mutant types which will be described in a later communication (Shatoury & Waddington, 1957b). In these lethals it is found that abnormality of the lymph glands is associated with and appears to be the cause of excessive hypertrophy of the larval cells composing the gut.

Developmental effects of some newly induced Ultrabithorax alleles of Drosophila

Development ◽  
1982 ◽  
Vol 68 (1) ◽  
pp. 211-234
Author(s):  
Stephen Kerridge ◽  
Gines Morata
Keyword(s):  
Chromosomal Aberrations ◽  
Abdominal Segment ◽  
Larval Period ◽  
Additive Effect ◽  
Bithorax Complex ◽  
Induced Mutations ◽  
Heterozygous Condition ◽  
X Ray ◽  
Developmental Effects ◽  
Blastoderm Stage

Nine X-ray-induced mutations of the bithorax complex (BX-C) have been isolated and characterized. They all show the typical features of the Ultrabithorax mutations. They are homozygous lethal, produce a slight enlargement of the haltere in heterozygous condition and fail to complement the mutations at the bx, bxd and pbx loci. Some of them are associated with chromosomal aberrations in the regions 89E 1-4, where the BX-C lies, while others appear normal cytologically. The effect of six of these mutants in the adult cuticle has been studied, producing mutant marked clones in heterozygous individuals. The clones were generated by X-radiation at two points in development: the blastoderm stage and the second larval period. In all cases mutant clones showed the same phenotype: clones appearing in the dorsal structures transform metathorax and first abdominal segment towards mesothorax. That is the additive effect of bx, bxd and pbx mutations. Clones in the legs, if induced during the larval period, show an effect homologous to that seen in the dorsal structures. However, when produced at blastoderm they show in addition a transformation of the posterior second (mesothoracic) and third (metathoracic) legs into the posterior first (prothoracic) leg. This transformation, named postprothorax (ppx) has been recently described for the alleles Ubx130 and Ubx1 (Morata & Kerridge, 1981) and appears to be general for the Ubxmutations. It is concluded that the realm of action of the Ubx gene is defined by part of the rflesothoracic segment (posterior second leg compartment) and the entire metathoracic and first abdominal segments.

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